Root-inducing transferred-DNA (Ri T-DNA)-transformed roots of tomato (Lycopersicon esculentum) were in vitro inoculated with surface-sterilized vesicular-arbuscular mycorrhizal leek root pieces. ...About 1 week after inoculation, the infection of the transformed root culture by the fungal endophyte was confirmed by photonic microscopy. Total proteins were extracted from the mycorrhizal roots and analyzed by two-dimensional polyacrylamide gel electrophoresis. Control gels were run with proteins extracted from noninoculated roots mixed with purified intraradical vesicles and extraradical hyphae. Comparison of the resulting patterns revealed the presence of two polypeptides with estimated apparent masses of 24 and 39 kDa that were detected only in infected roots. Polypeptides with similar migration parameters were not detected in roots challenged with spore extracts, suggesting that the accumulation of the polypeptides was directly linked to root colonization by the fungus rather than to induction by fungus-derived elicitors
Staphylokinase (Sak), a 16-kDa bacterial protein, forms a 1:1 stoichiometric complex with the serine proteinase domain of human plasmin, which in turn converts other plasminogen molecules into ...plasmin. To identify amino acid residues critical for generating the Sak:plasmin activator complex, alanine-scanning mutagenesis was performed on phage-displayed micro-plasminogen (μPlg). Substitution of Arg719 with Ala μPlg(R719A) disrupted complex formation, although the sensitivity of phage-displayed μPlg(R719A) to activation by urokinase and the amidolytic activity of the micro-plasmin derivative μPli(R719A) remained unaffected. Likewise, the soluble μPlg(R719A) molecule did not generate a functional activator complex with Sak, whereas quantitative activation into plasmin was obtained upon incubation with either urokinase or the Sak:plasmin complex. Real-time biospecific affinity measurements revealed that the Arg → Ala substitution at position 719 increased the equilibrium dissociation constant between μPlg(R719A) and Sak from 46 nM to 1 μM, primarily by reducing the association rate constant. Arg719 has recently also been implied in the functional complex formation between human plasmin and streptokinase Dawson, K. M., Marshall, J. M., Raper, R. H., Gilbert, R. J., and Ponting, C. P. (1994) Biochemistry 33, 12042−12047., suggesting that both bacterial cofactors may share common structural and/or mechanistic aspects for plasminogen activation.
Studien syftar till att undersöka sociala entreprenörers attityd till risk och om riskattityden har något samband med karaktärsdraget altruism. Tidigare forskning jämför traditionella entreprenörer ...med sociala entreprenörer i relation till risk och har funnit olika resultat. En av anledningarna är att risk är komplext och kan undersökas på olika sätt. Dessutom varierar definitionen av socialt entreprenörskap mellan olika studier, områden och länder. Vår studie använder sociala entreprenörer som målgrupp utifrån en bestämd definition och tar genom en enkät reda på deras attityd till risk. Till följd av tidigare studier som riktat in sig på olika personligheter och karaktärsdrag inom vår målgrupp valde vi att studera karaktärsdraget altruism och dess påverkan på riskattityden. Studien undersöker på vilket sätt entreprenörernas grad av altruism kan vara kopplad till deras riskattityd. Insamlade data från 100 sociala entreprenörer används som underlag för Spearman r korrelationstester. Respondenternas svar på olika riskfrågor skapar ett riskindex som sedan analyseras mot deras svar på frågor om altruism. Resultatet visar att det finns korrelationer mellan vissa svar om altruism och riskindexet vilket betyder att altruism är en påverkningsfaktor för sociala entreprenörers riskattityd. Respondenterna visade sig vara relativt riskneutrala med tendens åt det riskaverta hållet mer än att vara risksökande. Vidare visar resultatet att kvinnliga och manliga sociala entreprenörer får vissa liknande samband och vissa helt olika. Dessutom finner studien fler samband mellan de respondenter som anser sig utveckla affärsmässiga lösningar på samhällsproblem jämfört med de som inte gör det.
The purpose of this paper is to examine if social entrepreneurs’ risk attitude is correlated to the specific characteristics of their altruism. Previous research has shown different results when comparing traditional entrepreneurs with social entrepreneurs in relation to risk. One of the reasons for this is that risk as a subject is complex and can be studied in many different ways. The definition of social entrepreneurship also varies between different research contexts and countries. The target group in our research is social entrepreneurs from a set definition, and with the use of a survey we find out their attitude towards risk. Previous research has also emphasized the importance of the target groups personalities, characteristics and other traits. Our study originated from the characteristic altruism and its effect on social entrepreneurs’ risk attitude. This study investigates in which way the degree of altruism can correlate to the risk attitude. Data from 100 social entrepreneurs is used to carry out Spearman r correlation in the data. The respondents answers to questions about risky situations created a risk index which was subsequently compared to their answers regarding altruism. The results showed correlations between a number of answers to the questions concerning altruism and the risk index, which means that altruism influence their risk attitude. The respondents turned out to be risk neutral with a tendency towards more risk averse than risk seeking. Furthermore, the results show that the female and male social entrepreneurs have some similar correlations and some with a distinct difference. There are also differences in the results between the respondents who answered yes and no to the question about whether or not they develop business solutions for social problems.This study is written and conducted in Swedish.
Two low‐molecular‐mass forms of human plasminogen, plasminogen‐(543–791)‐peptide (micro‐plasminogen), comprising the serine protease domain, and plasminogen‐(444–791)‐peptide (mini‐plasminogen), ...which in addition contains kringle 5, were displayed on filamentous phage by fusion to the N‐terminus of the minor coat protein pill, to levels of 0.5 molecules micro‐plasminogen–pIII/phage particle and 0.1 molecules mini‐plasminogen–pIII/phage particle. The proenzymes, quantitatively activated by urokinase, showed catalytic efficiencies that were virtually identical to their soluble counterparts, and activity remained associated with the phage as demonstrated by phage ELISA and biopanning with human α2‐antiplasmin or the inhibitor Phe‐Pro‐Arg‐CH2Cl. Micro‐plasminogen–pIII was activated by streptokinase and staphylokinase, two non‐enzymatic plasminogen activators, to the same extent as by urokinase. Activated forms of mini‐plasminogen–pIII, micro‐plasminogen–pIII and mini‐plasminogen dissolved 125I‐labelled fibrin films in a dose‐dependent time‐dependent manner, with 50% lysis in 20 h requiring 0.52, 3.2 and 0.46 nM active plasmin, respectively. Thus, proenzyme moieties derived from plasminogen can be successfully displayed on phage with maintenance of their enzymatic properties. The micro‐plasminogen and mini‐plasminogen phage‐display systems may be useful to study mechanisms of plasminogen activation.
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